The present invention relates to cosmetic surgery in general; and, to dermal abrasion, in particular.
The peeling of skin from the human body is well known for cosmetic purposes. While it is particularly well known in the context of facial cosmetic surgery, for the peeling of aging, wrinkled, or otherwise blemished skin, it is also known for the peeling of skin from other parts of the body, such as from the feet.
Among known methods of cosmetic skin peeling are dermal abrasion, and chemical peeling. Known dermal abrasion techniques include either the use of various mechanical methods so as to remove unwanted skin; or the use of irradiation treatments of various types, including the employment of laser surgical techniques. Chemical peeling involves the application of a film-forming chemical substance to the skin sought to be peeled, and subsequently removal of the film together with an outer layer of the epidermis. See, for example, the review article xe2x80x9cThe use of glycolic acid as a peeling agentxe2x80x9d by Murad, Shamban, and Premo in Dermatologic Clinics 13(2), 1995.
The above-mentioned methods are characterized by various disadvantages, including recuperative periods which can last from several days to several months. Known methods of dermal abrasion, furthermore, can be very painful and cause a large amount of bleeding while being performed. The use of laser methods, moreover, requires very expensive equipment, consuming large amounts of energy; which, if improperly used, can cause severe bum damage to a patient. Many of these problems and limitations are reviewed in xe2x80x9cA peelers thoughts on skin improvement with chemical peels and laser resurfacingxe2x80x9d by M. G. Rubin in Clinics in Plastic Surgery 24(2) 1997.
Furthermore, the above methods generally require performance by and the supervision of skilled medical personnel, and cannot generally be performed by users in a domestic environment.
The present invention seeks to provide a novel apparatus and method of dermal abrasion, which overcome disadvantages of the known art.
There is thus provided, in accordance with a preferred embodiment of the invention, apparatus for dermal abrasion, which includes:
a container for a sterile liquid;
a fluid delivery head having a liquid entry port and a gas entry port, a fluid outlet, and a valve located between the entry ports and the fluid outlet, for selectably permitting respective liquid and gas flows from the entry ports to the fluid outlet;
a liquid conduit extending between a liquid inlet located within the container and a liquid outlet connected to the liquid entry port of the delivery head;
a gas conduit extending between a gas inlet and a gas outlet, wherein the gas inlet is connected to a source of pressurized gas and the gas outlet is connected to the gas entry port of the delivery head, and wherein the gas conduit is connected to the container via an intermediate outlet port; and
apparatus for selectably exposing the source of sterile liquid to a flow of pressurized gas flowing from the gas inlet to the gas outlet and into the gas entry port of the fluid delivery head, thereby to pump the sterile liquid along the liquid conduit, from the inlet to the outlet, and into the liquid entry port of the fluid delivery head, and
apparatus wherein the fluid outlet has one or more nozzle members arranged to receive the gas and liquid flows and to combine them into a corresponding number of gas-liquid outflows which exit the apparatus through the fluid outlet in the form of sterile liquid mist jets suspended in a high velocity gas stream, and wherein the jets are operative, when brought to within a preselected distance from the skin surface to be abraded, to separate therefrom at least a portion of the epidermis.
Additionally in accordance with a preferred embodiment of the present invention, the gas flow exits the valve into the gas-liquid combining member at a pressure of a first magnitude, and the combining member is operative to cause a pressure drop in the gas flow therethrough such that the pressure of the gas-liquid outflow downstream of the fluid outlet, is of a second magnitude, wherein the first magnitude is at least twice the second magnitude, so as to cause a shock wave in the gas-liquid flow downstream of the fluid outlet and atomizing of the liquid portion of the outflow into microscopic droplets, thereby to form a mist suspended in the gas portion of the outflow.
Further in accordance with a preferred embodiment of the present invention, at least a portion of the gas-liquid outflow downstream of the fluid outlet, has a sonic or supersonic velocity.
Additionally in accordance with a preferred embodiment of the present invention, the gas inlet of the gas conduit is constructed for connection to a pressurized gas source, and the outflow is an outflow of the sterile liquid mist suspended in a high velocity gas stream.
Further in accordance with a preferred embodiment of the present invention, the fluid outlet is configured so as to apply a suction force in the vicinity of the skin surface being abraded so as to remove tissue debris therefrom.
Additionally in accordance with a preferred embodiment of the present invention, the fluid outlet defines a fluid outlet port having a predetermined diameter and a preselected distance of operation; that is, the distance between the skin being abraded and the nearest portion of the delivery head to the skin being treated; wherein this distance of operation is not greater than 50 times and preferably within a range of 1-5 times the predetermined diameter.
Further in accordance with alternative embodiments of the present invention, the sterile liquid optionally contains predetermined amounts of crystalline or other microscopic particles to increase its abrasive properties, or of chemicals which cause peeling of the outer skin layers.
There is also provided, in accordance with a further preferred embodiment of the invention, a method of dermal abrasion, which includes:
exposing a source of sterile liquid to a flow of pressurized gas, thereby to cause a pumped supply thereof into a fluid delivery head;
supplying the pressurized gas to the fluid delivery head;
combining the gas and liquid supplied to the delivery head, wherein the fluid delivery head has a fluid outlet with a predetermined internal diameter, so as to provide a gas-liquid outflow in the form of a sterile liquid mist jet suspended in a high velocity gas stream; and
exposing to the mist jet, at a preselected distance from the fluid outlet, a portion of the skin surface sought to be abraded, thereby separating therefrom at least a portion of the epidermis and removing therefrom the resulting tissue debris.
Further in accordance with a preferred embodiment of the present invention, the preselected distance is not greater than 50 times and preferably within a range of 1-5 times the predetermined internal diameter.
Additionally in accordance with the method of the invention, the step of supplying the pressurized gas includes supplying the gas at a pressure of a first magnitude, and the step of combining includes causing a pressure drop in the gas flow such that the pressure of the gas-liquid outflow, is of a second magnitude, wherein the first magnitude is at least twice the second magnitude, so as to cause a shock wave in the gas-liquid outflow and atomizing of the liquid portion of the outflow into microscopic droplets, thereby to form a mist suspended in the gas portion of the outflow.
Preferably, at least a portion of the outflow has either a sonic or supersonic velocity.
Further in accordance with a preferred embodiment of the present invention, the method also includes the steps, prior to the step of combining, of
providing a gas outflow;
causing an expansion of the gas outflow, thereby to cause a reduction in the pressure thereof to sub-atmospheric pressure, thereby to provide a suction force; and
providing a liquid outflow in conjunction with the expanded gas outflow.